Heat Pump ?s

I've done a fair bit of my own hvac work. I replaced a couple of gas
furnaces and one split ac. I'm building a new garage with living
space above it out at my lake house. I picked up a "slightly" used
goodman 1 1/2 ton heat pump compressor off craig's list. It was
installed as part of an attic conversion that was never completed.
While the seller was moving out of the house the low side line was
damaged and it lost charge. Fast according to the seller.
The guy didn't know enough to shut the valves. Instead he hacksawed
off the lines. Folded the small one over and stuffed a piece of foam
in the big one. I cut them off with a pipe cutter, closed the valves,
and blew them out with compressed air. I was worried that I probably
did not get all the copper filings from the hacksaw so I opened the
valves and blew the lines out again via the third tap. (The one that
is used to check pressure during heat mode.) I didn't get a lot of
air to move through it though that way so I doubt I blew out any more
filings.
So I'm worried that there still may be some copper filings in the
lines. What else can I do?
I'm also a little worried that it may have lost some oil when the low
side was broken. There doesn't seem to be any easy way to drain and
refill the oil though.
I won't be installing it from a few months. I'd like to go ahead and
vaccum it down. Can I do that via the third tap? I'll fill it with
some r22 after I vacuum it.

Using R11 in liquid form makes for a very good solvent in cleaning out
a contaminated system but youll have to get someone in the Trade to
get some for you ; its not available for Consumers. Short of that,
I would first vaccuum out the lines as best you can then replace the
liquid line filter drier which may have come with the Heat Pump unit
already installed, or, add an external Bi-Flow type just outside of
the unit in the liquid line once you are installing the Unit . You can
add a small amount of Refrigerant Oil for the compressor via the open
Suction Line , so when the system is put into operation (cooling
mode) , it will suck the added oil into the crankcase of the hermetic
compressor ; id find out the total oil capacity for that specific
compressor and add 10-15% of the total capacity it is supposed to
contain . Use the correct oil -- it doesnt take 10w30 Oil ! Its a
special oil formulated for A/C compressors.

I've done a fair bit of my own hvac work. I replaced a
couple of gas
furnaces and one split ac.
CY: yes, those are good skills to have.
I'm building a new garage with living
space above it out at my lake house. I picked up a
"slightly" used
goodman 1 1/2 ton heat pump compressor off craig's list. It
was
installed as part of an attic conversion that was never
completed.
While the seller was moving out of the house the low side
line was
damaged and it lost charge. Fast according to the seller.
The guy didn't know enough to shut the valves. Instead he
hacksawed
off the lines. Folded the small one over and stuffed a
piece of foam
in the big one.
CY: Compressor oil absorbs moisture from the air. When you
go to reinstall, you should vacuum the system to 500
microns, and leave the vacuum pump running at least an hour.
Also, please install an ovesize filter drier, as you may
have a lot of moisture trapped.
I cut them off with a pipe cutter, closed the valves,
and blew them out with compressed air. I was worried that I
probably
did not get all the copper filings from the hacksaw so I
opened the
valves and blew the lines out again via the third tap. (The
one that
is used to check pressure during heat mode.) I didn't get a
lot of
air to move through it though that way so I doubt I blew out
any more
filings.
So I'm worried that there still may be some copper filings
in the
lines. What else can I do?
CY: Liquid and suction line filter driers comes to mind.
I'm also a little worried that it may have lost some oil
when the low
side was broken. There doesn't seem to be any easy way to
drain and
refill the oil though.
CY: That's right, there is no easy way.
I won't be installing it from a few months. I'd like to go
ahead and
vaccum it down. Can I do that via the third tap?
CY: How about cap the lines, and then vac through the usual
service ports?
I'll fill it with
some r22 after I vacuum it.
CY: Well, enough R-22 to keep air and moisture out. 30 PSI
or so should help.

Blowing compressed air into the unit was a little bit
of a bad move. People in the HVAC and refrigeration
trades use dry nitrogen for internal clean out along
with a suitable solvent for coils detached from the
compressor. Compressed air can carry moisture into a
system when blown through it. R11 isn't used as freely
as it once was because it kills the poor defenseless
little ozones. I use a product called CF-20 Internal
Coil Cleaner available at many HVAC supply houses and
it's available without any special permit:
http://tinyurl.com/lk2uq3
You would have been better off leaving the valves closed
and flushing out the pipe stubs with freeze spray which
is basically a freon mix of some sort or even dust blaster
which will blow the stuff out and leave no residue. The
low side line being pierced would not cause an appreciable
oil loss from an un-powered unit. Because of the compressed
air introduced to the system you will need to pull a deep
vacuum on the system. The warmer it is when you do it, the
better it will pull out the moisture. Of course a good sized
liquid line dryer like a C-163 Sporlan which is a 3/8 flare
dryer which makes for easy replacement. I always add a sight
glass with a moisture indicator to all the systems I install.
You can get one that will screw right on to the C-163 and
and attach to the tubing with a flare fitting. Heck, HVAC
work isn't rocket surgery, Storman Norman does it. *snicker*
TDD

After a long day of breaking refrigeration and AC units all
over the tri county area, and leaving destruction in my
wake. I come home.... to THIS!
"Why, you'd think they were all my wife!"
Maj. Frank Burns, MASH 4077th.

The valves weren't closed when I got it so I figured the compressed
air was not going to make much difference at this point. I don't have
a nitrogen tank. My supplies are a vacuum pump, set of gauges, a can
of r22. My brazing skills are sketchy so I try to minimize that. I'd
like to have a nitrogen tank but so far I've gotten away without.
I'll go ahead and pump it down and fill it with r22. I'm guessing
it's ok to do that using that middle tap?
It has a filter/dryer on the high side. I can add one to the low
side. The guy moved it from one house to the another and kept it in a
shed. So it got moved around a bit. I'm afraid that there may be
some copper filings further down the low side line inside the unit
that I can't really get to. What happens when they go into the
compressor? Will they just end up sitting in the bottom in the oil?
Or the switching valve? Are these things engineered anticipating that
occasional small solid might get in? This is my biggest worry. The
moisture I can get out with my vacuum pump.

Around here it's dirt daubers/mud daubers and other flying
or crawling critters you have to worry about when a pipe is
left open. The little bit of copper filings isn't a big concern.
The vacuum needs to be drawn from both high and low service
fittings through the gauge set. If you're worried about moisture,
why on earth are you not replacing the liquid line dryer?
The dryer is the first thing to replace, just don't leave it
open to the air for any longer than it takes to install it.
Since it's a heat pump, it requires biflow or bidirectional
dryers because the refrigerant flow is reversed when changing
from heat to cool. If you're worried about trash getting into
the reversing valve, the best thing to do would be to remove
the section of large diameter tubing and clean it out. Make
sure you wrap a wet rag around the reversing valve when using
your torch near it. You can always cut the tubing a distance
away from the reversing valve and braze it back together with
a coupling. A lot of service techs are using a low temperature
silver solder on HVAC equipment which doesn't require the use
of oxygen-acetylene torches.
TDD

Guess I should add it's not been so open that bugs could get in. It's
just that the service valves were never closed. The high side line
was folded over. A piece of the low side foam was stuck in the low
side pipe.

I assumed you were referring to pulling a vacuum after installation,
not for storage purposes. If the pipes were plugged up in any fashion,
there shouldn't be much moisture infiltration since there would still
be mostly freon in the system. The dryer should still be replaced when
it is finally installed. Since you have no nitrogen, R22 would be fine
for putting a slight pressure on the unit for storage but when
installed, it will still need a deep vacuum drawn on it. When me and
my friends install a new system in the field, we pressurize it with
nitrogen and leave it that way before ever pulling a vacuum and opening
the valves for startup. If we don't leave the condenser because of
the theft problem with new construction, we cap the line set and
pressurize it with nitrogen until it's time for occupation. That way
we have no surprise leaks such as those caused by other tradesmen
putting a nail or screw through a pipe. The thing about dry nitrogen
is that the static pressure is not going to change perceptively with
a change in temperature. If you pressurize for a leak test and come
back a week later when the weather has changed, the test pressure
will be the same if there are no leaks.
TDD

I gotta store it for a while. The garage/rec room is under
construction at the moment. It's about done with the framing/
exterior. My back is shot so I had to hire a local guy to do most of
that. I'm going to do the plumbing/electrical/hvac after he's
finished. Then I'll get someone back in to do the drywall, my back's
too bad for that as well. I picked this unit up because I've been
collecting stuff off craig's list local materials for a few months
now. If you know what you need and are not in a hurry it's a good way
to get supplies cheap. Lots of new items where someone changed their
mind or bought too many. This was $250 and johnstons wants $899 for
it. Some risk on my part but hey that's life.
I'll pull a vacuum via the third service port and follow up with a
little r22 into it.
I wouldn't mind having a nitrogen tank but a bargain hasn't come along
yet :-)

Keep looking, I found both of mine abandoned. Of course
over the years I've exchanged them numerous times but I
didn't have to pay that initial $135.00 or whatever it
is now. I have two "Q" sized cylinders and I bought a
good regulator which has the same fitting as an oxygen
regulator but is for inert gas. Dry nitrogen is some
very handy stuff to have around. I also have a gaggle
of 20lb CO2 cylinders that are for soft drink fountains.
Those are extremely useful when used with a high flow
regulator for blowing out condensers, clearing drains,
running air tools or inflating tires. I've found all
manner of tanks in dumpsters and as door props. Darn,
I have a bunch of propane tanks too. I'd make good
terrorist.
TDD

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